Hypothalamic and Pituitary Imaging Flashcards
Available imaging modalities
- MRI is only logical thing to order
- Can do a CT if MRI is contraindicated (ex. cardiac pacemaker, nerve root stimulators)
- No ionizing radiation
- Can be performed in any plane
- Measures 3 things only:
- Proton density
- T1 relaxation rate
- T2 relaxation rate
- Contrast only affects T1
T1 and T2: relaxation rate, colors, common bright items
Appearance of hypothalamic-pituitary structures on imaging (1 of 3, non-contrast primary T1)
Appearance of hypothalamic-pituitary structures on imaging (2 of 3, non-contrast primary T1)
Appearance of hypothalamic-pituitary structures on imaging (3 of 3, post-constrast T1)
Normal appearance of pituitary and sella on imaging (T1 weighted)
Normal appearance of pituitary and sella on imaging (T2 weighted)
Radiologic appearance of macroadenoma
- Remodels bone, doesn’t bust through (insidious)
- Dumbbell shape as it squeezes through sella
- Mass effets come from growth –> optic chiasm, cavernous sinuses, can collapse arteries
- Cavernous sinuses are dural folds (difficult to approach by neurosurgery)
- Regardless of size and expansion: still staged as adenoma, not carcinoma until distant metastases present
Radiologic diagnosis?
Hyperplasia of pituitary
Radiologic diagnosis?
Pituitary microadenoma
- Right side of adenohypophysis is enlarged
- Focal decreased enhancement in this region
- T2 signal is low
Radiologic diagnosis?
- Giant pituitary macroadenoma (> 4 cm)
- Invasion of clivus, sphenoid sinus, ethmoid air cells, and nasal vault
Radiologic diagnosis?
Rathke Cleft cyst
Radiologic diagnosis?
Lymphocytic hypophysitis
Radiologic diagnosis?
Craniopharyngioma: adamantinomatous type (2 year old child, most commonly calcified in children)
Radiologic diagnosis?
Craniopharyngioma: papillary type
Radiologic diagnosis?
Meningioma
